The Rudolph J57WR Automatic Digital Refractometer was designed to meet the unique needs of industrial environments in the chemical industry where the refractometer is viewed as a Quality Control (QC) tool rather than a laboratory instrument. A single flat measurement surface, automatic electronic temperature control and one button measurement capability make it perfect for heavy use applications where fast, automatic, and accurate readings are required.
The Rudolph J57WR features a fully automatic measuring system. The operator simply places the sample on the prism, presses a button and the digital results are displayed on a 7.5cm x 10cm back lit LCD screen. There are no shadow lines to match and there is no eyepiece requiring operator determination or manual adjustment.
Refractive Index (BRIX) readings are very sensitive to temperature. When measuring sucrose users have the option of correcting for temperature variation but that option does not work for most chemical companies. Users not measuring sucrose or users looking for better accuracy than provided by temperature correction had to spend the extra money for a circulating water bath and then clean and maintain it. The J57WR’s built in electronic temperature control system provides the best of both worlds, the absolute accuracy, regardless of sample type, of a temperature controlled instrument with the convenience of operating without a water bath.
The J57WR was designed for chemical measurement, not food. This means a very wide measurement Refractive Index (RI) range from 1.26 - 1.70 is available thus enabling the instrument to measure materials like fluorocarbons and aromatic chemicals that are beyond the range of most refractometers.
Regardless of the specified instrument accuracy the real world performance will always depend on how well the instrument is cleaned between samples. The Rudolph Research J57WR addresses this issue by providing a very flat easy to clean measurement surface with no corners or crevices that tend to trap samples in instruments designed for laboratory use.

When a traditional refractometer is used in a high throughput application, prism replacement becomes a regular task. Traditional Abbe refractometers have glass prisms which are much softer than the rugged sapphire prism of the J Series and thus more prone to scratching and general wear and tear.
Users in high throughput chemical applications have traditionally used Abbe refractometers due to their low initial purchase price. Changes in relative prices between refractometers and optics and the elimination of a water bath mean the J57WR now delivers a much lower total cost over the life of the instrument than an Abbe refractometer. The speed and accuracy of readings also increases productivity and reduces costly mistakes that can be potentially caused by inaccurate readings.
The J57WR Automatic Refractometer offers 1 or 2 point calibration. The instrument stores the date and the time of the last calibration in line with ISO and similar standards. Regardless of how many times the refractometer is calibrated it can always be restored to the default factory calibration.
Versatile laboratory instruments have advantages when applications change however this versatility can also lead to confusion with extra buttons and by forcing operators to interpret extra results that have no relevance. The Rudolph J Series customizable display allows the instrument to be configured to exactly what is required for each application. The customizable digital keypad can be "locked out" or just a few keys can be operable, i.e. the measure key, print key, zero key, customer specified sample keys or any combination thereof. The lockout function, calibration and other functions are all password protected.
All functions of the J57WR Automatic Refractometer are activated through a large touch screen, digital LCD. The 70mm X 75mm measure button on the J57WR is designed to allow an operator wearing gloves to activate measurement with an elbow or side of a hand. The sealed touch screen is resistant to fingernails, sharp objects, chemicals and acids.
A combination of password protection and being able to lock out specific "keys" enables control over which users can access certain functions. This means that the J57WR can be set up as a one-button instrument for high production factory environments.
In today's highly regulated environment many users find hard copy or computer record keeping essential. The J57WR comes complete with a standard centronics port for a printer and an RS232 port for direct computer connection to facilitate a permanent information trail.
Rudolph Research Analytical manufactures automatic, digital, bench-top refractometers for a wide variety of industries. With over 5,000 laboratory instruments installed in demanding applications worldwide and thousands still in use that were manufactured in the 70s, 80s, and 90s, Rudolph has established itself as a premier vendor well known for its quality and reliability. Rudolph has also consistently set the pace for innovative design and features that bring new and important functionality to its market leading line of refractometers. Our service and responsiveness come from a deep commitment to serving our customers with integrity, quality and innovation that we have maintained for over 50 years. Please read one of our customer testimonials.